This research is focused on evaluation and modification of fear in children, employing behavioral techniques developed from learning theory. A population of normal children in need of dental treatment will provide opportunity to study measurement of fear and methods by which reaction to stress can be altered. In order to accomplish this goal a multidimensional approach to the measurement of the fear construct will be undertaken to assess change in the subjective experience of pain, the psychophysiological correlates of the dental experience, and the disruptive behaviors which signal and augment fear- related responses in children. Behavioral methods to improve the efficiency of dental treatment by minimizing the behaviors which interfere with dental therapy will be evaluated for both effectiveness and theoretical relevance. Normal, lower socio-economic level boys and girls receiving treatment will be prepared by film modeling techniques. The adequacy of a "coping" versus "Mastery" peer model will be tested. The vicarious reinforcement derived from observing the response consequences to the model as administered by the videotaped dentist will be studied. The patient-dentist interaction, regarding the dentist's use of positive reinforcement, negative reinforcement, contingent positive and negative, and no evident consequences (neutral), will be studied in relation to disruptive behaviors, and other fear manifestations in the children. The interaction between the use of a modeling film that produces optimal cooperation and the types of reinforcement that the dentist uses will be evaluated.